What you see here is an Osram HQI-T 250W/D pulse start metal halide lamp designed for the European market running in a grow light fixture that uses a North American 250W S50 high pressure sodium CWA ballast. The reason I used a North American 250W S50 high pressure sodium ballast for this Osram pulse start metal halide lamp is due to the fact they have virtually the same arc voltage drop and operating current as virtually all 250W high pressure sodium lamps in the world. Although these lamps generally need a higher voltage ignitor pulse than 250W high pressure sodium lamps, this lamp managed to immediately strike an arc upon applying power to the fixture even though the fixture still uses its original ignitor. Interestingly, even though the lamp is generally intended to require a ballast OCV somewhere around 220-240V, it still struck an arc despite the fact that the ballast’s actual OCV is somewhere around 180V. While watching the lamp warming up, it emits a beautiful seafoam green color that can’t be observed with most other metal halide lamps that I have seen. When the lamp reaches full brightness, it emits a very beautiful daylight white color with an excellent color rendering index above 90!!!
8 сен 2024
